New Build.. Cooling Problem?

[IntegratedTJ]

Got a 1972 Chevy C10 - So I just rebuilt my motor after it warped the heads due to lack of cooling (Thermostat pooped out and I didn't have a temp gauge) and I am running a JEGS Mechanical Water Temp Gauge, the sending unit part is installed in the top of the intake manifold on the passenger side. I am new to mechanical gauges AND engine building, however it runs great and.. am I just paranoid? The gauge randomly spikes up to 200-230 but then immediately goes back down to 185-195. I was just wondering if this is something to worry about or am I just paranoid? My theory was that maybe it was the hot coolant circulating out of the engine on that passenger side and the cooler coolant circulating in behind it? Thanks in advance!